1. Field of the Invention
The present invention relates to a device for controlling the rotating state of an engine.
2. Description of the Related Art
Conventionally, in a small boat such as a motor boat, a steering device, a shift device and other components are mechanically connected to an engine of an outboard motor. In order to improve the operability of the boat during steering using a communication technology, the communication technologies described in JP-B-Hei 7-22288 and JP-B-3797049 have been used. More specifically, a boat including a remote control device arranged to remotely control an engine is known. The boat includes an engine side ECU (Engine Control Unit) as an “engine side control unit” on the engine side to which a steering wheel device, a gear box and other components of the remote control device are connected via a signal line, such as a wiring harness, and an engine rotation control device arranged to control the rotational speed of the engine by remote control from the remote control device. When trolling is performed using such a boat, the boat must be continuously moved at a slow speed such that the end of the fishing line can be consistently positioned in a region in which fish are present. Thus, the operator moves the boat forward (or backward) slowly by alternating between a state in which the gear is in a forward (or reverse) position and a state in which the gear is in a neutral position for short time periods (this manner of traveling is referred to as “slow-speed cruising” in this specification). To achieve slow-speed cruising by operating the shift lever, the operator must repeatedly shift the remote control shift lever in the cockpit between the forward (or reverse) position and the neutral position in short periods of a few to several dozens seconds, resulting in a burden on the operator. Therefore, it is known to enter the time periods for which the forward (or reverse) gear is to be used and the time periods for which the neutral gear is to be used into programs in advance and to provide an operation button on a gauge for displaying prescribed measured values from the engine so that a desired program can be started by operating the operation button to cause a microcomputer incorporated in the engine side ECU to perform control functions required to achieve a desired slow-speed cruising.